Which of the following statements are true? Mass and matter are always the same
Mass can decrease while matter increases
Matter is made up of atoms and has mass
Ater does not exist in biosphere

i think its the first one

sheep is a herbivore animal whereas grasshopper belongs to the class chordates but both of them feed on greens.  

if grasshopper and sheep feeding on a pasture land, i do not think both of them will have any impact on each other. however, the number of the species can make difference. since sheep feed on greens, there is a possibility there left no pasture land for the grasshoppers or they may get extinct.